Perhaps you should try some spelling variations:
khoan khau » khoanh khac, khoa kham, khoa phau
khau thong » khau thuong, khap thong, khau tong
sach tren » sach tien, sach tranh
dan thong » dan trong, ban thong, dan phong
cach tri » cach thoi, cac tro, cach noi
hoc sach » hoc sinh, hoc cac, hoc anh
tren tue » tren que, tren thuc, tren thi
tue bach » truc bach, thi bach, vu bach
bach hoa » bach khoa, bach ha, cach hoan
tu cach » tu cac
tue cac » tu cac, tuc cac, te cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu cach tri tue cac khoan khau thong ) or ( hoc sach tren tue bach hoa dan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu cach tri tue cac khoan khau thong ) OR ( hoc sach tren tue bach hoa dan thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu cach tri tue cac khoan khau thong ) or ( hoc sach tren tue bach hoa dan thong ))*.